Literatura académica sobre el tema "Chemiresistive gas sensor"
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Artículos de revistas sobre el tema "Chemiresistive gas sensor"
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Schober, Sebastian A., Yosra Bahri, Cecilia Carbonelli y Robert Wille. "Neural Network Robustness Analysis Using Sensor Simulations for a Graphene-Based Semiconductor Gas Sensor". Chemosensors 10, n.º 5 (21 de abril de 2022): 152. http://dx.doi.org/10.3390/chemosensors10050152.
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Despite their advantages regarding production costs and flexibility, chemiresistive gas sensors often show drawbacks in reproducibility, signal drift and ageing. As pattern recognition algorithms, such as neural networks, are operating on top of raw sensor signals, assessing the impact of these technological drawbacks on the prediction performance is essential for ensuring a suitable measuring accuracy. In this work, we propose a characterization scheme to analyze the robustness of different machine learning models for a chemiresistive gas sensor based on a sensor simulation model. Our investigations are structured into four separate studies: in three studies, the impact of different sensor instabilities on the concentration prediction performance of the algorithms is investigated, including sensor-to-sensor variations, sensor drift and sensor ageing. In a further study, the explainability of the machine learning models is analyzed by applying a state-of-the-art feature ranking method called SHAP. Our results show the feasibility of model-based algorithm testing and substantiate the need for the thorough characterization of chemiresistive sensor algorithms before sensor deployment in order to ensure robust measurement performance.
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Zhou, Guangying, Bingsheng Du, Jie Zhong, Le Chen, Yuyu Sun, Jia Yue, Minglang Zhang et al. "Advances in Gas Detection of Pattern Recognition Algorithms for Chemiresistive Gas Sensor". Materials 17, n.º 21 (24 de octubre de 2024): 5190. http://dx.doi.org/10.3390/ma17215190.
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Gas detection and monitoring are critical to protect human health and safeguard the environment and ecosystems. Chemiresistive sensors are widely used in gas monitoring due to their ease of fabrication, high customizability, mechanical flexibility, and fast response time. However, with the rapid development of industrialization and technology, the main challenges faced by chemiresistive gas sensors are poor selectivity and insufficient anti-interference stability in complex application environments. In order to overcome these shortcomings of chemiresistive gas sensors, the pattern recognition method is emerging and is having a great impact in the field of sensing. In this review, we focus systematically on the advancements in the field of data processing methods for feature extraction, such as the methods of determining the characteristics of the original response curve, the curve fitting parameters, and the transform domain. Additionally, we emphasized the developments of traditional recognition algorithms and neural network algorithm in gas discrimination and analyzed the advantages through an extensive literature review. Lastly, we summarized the research on chemiresistive gas sensors and provided prospects for future development.
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Kim, Myeong Gyu y Yun-Hyuk Choi. "Gas-Sensing Properties of Co9S8 Films Toward Formaldehyde, Ethanol, and Hydrogen Sulfide". Materials 17, n.º 23 (24 de noviembre de 2024): 5743. http://dx.doi.org/10.3390/ma17235743.
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The chemiresistive gas-sensing properties of pristine Co9S8 film are little known despite its potential as a promising gas sensor material due to its intrinsic characteristics. In this study, a pristine polycrystalline Co9S8 film (approximately 440 nm in thickness) is fabricated by depositing a Co3O4 film followed by sulfidation to investigate its gas-sensing properties. The prepared Co9S8 film sensor is found to exhibit high responsiveness towards formaldehyde (HCHO), ethanol (C2H5OH), and hydrogen sulfide (H2S) at operating temperatures of 300 °C and 400 °C, with strong concentration dependence. On the other hand, the sensor shows very low or no responsiveness towards hydrogen (H2), acetone (CH3COCH3), and nitrogen dioxide (NO2). These results enhance our understanding of the intrinsic gas-sensing properties of Co9S8, aiding in the design and fabrication of high-performance chemiresistive gas sensors based on Co9S8.
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Bezdek, Máté J., Shao-Xiong Lennon Luo, Kang Hee Ku y Timothy M. Swager. "A chemiresistive methane sensor". Proceedings of the National Academy of Sciences 118, n.º 2 (31 de diciembre de 2020): e2022515118. http://dx.doi.org/10.1073/pnas.2022515118.
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A chemiresistive sensor is described for the detection of methane (CH4), a potent greenhouse gas that also poses an explosion hazard in air. The chemiresistor allows for the low-power, low-cost, and distributed sensing of CH4 at room temperature in air with environmental implications for gas leak detection in homes, production facilities, and pipelines. Specifically, the chemiresistors are based on single-walled carbon nanotubes (SWCNTs) noncovalently functionalized with poly(4-vinylpyridine) (P4VP) that enables the incorporation of a platinum-polyoxometalate (Pt-POM) CH4 oxidation precatalyst into the sensor by P4VP coordination. The resulting SWCNT-P4VP-Pt-POM composite showed ppm-level sensitivity to CH4 and good stability to air as well as time, wherein the generation of a high-valent platinum intermediate during CH4 oxidation is proposed as the origin of the observed chemiresistive response. The chemiresistor was found to exhibit selectivity for CH4 over heavier hydrocarbons such as n-hexane, benzene, toluene, and o-xylene, as well as gases, including carbon dioxide and hydrogen. The utility of the sensor in detecting CH4 using a simple handheld multimeter was also demonstrated.
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Je, Yeonjin y Sang-Soo Chee. "Controlling the Morphology of Tellurene for a High-Performance H2S Chemiresistive Room-Temperature Gas Sensor". Nanomaterials 13, n.º 19 (5 de octubre de 2023): 2707. http://dx.doi.org/10.3390/nano13192707.
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A two-dimensional (2D) van der Waals material composed only of tellurium (Te) atoms—tellurene—is drawing attention because of its high intrinsic electrical conductivity and strong interaction with gas molecules, which could allow the development of high-performance chemiresistive sensors. However, the correlation between the morphologies and gas detection properties of tellurene has not yet been studied in depth, and few reports exist on tellurene-based hydrogen sulfide (H2S) chemiresistive sensors in spite of their strong interaction with H2S molecules. Here, we investigate the morphology-dependent H2S gas detection properties of tellurene synthesized using a hydrothermal method. To tailor the morphologies of tellurene, the molecular weight of the surfactant was controlled, revealing that a 1D or 2D form was synthesized and also accompanied with the high crystallinity. The 1D tellurene-based chemiresistive sensor presented superior H2S detection properties compared to the 2D form, achieving a gas response (Rg/Ra) of ~38, even at room temperature. This outstanding performance was attributed to the high intrinsic electrical conductivity and high specific surface area of the resultant 1D tellurene.
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Zhang, Run, Cong Qin, Hari Bala, Yan Wang y Jianliang Cao. "Recent Progress in Spinel Ferrite (MFe2O4) Chemiresistive Based Gas Sensors". Nanomaterials 13, n.º 15 (27 de julio de 2023): 2188. http://dx.doi.org/10.3390/nano13152188.
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Gas-sensing technology has gained significant attention in recent years due to the increasing concern for environmental safety and human health caused by reactive gases. In particular, spinel ferrite (MFe2O4), a metal oxide semiconductor with a spinel structure, has emerged as a promising material for gas-sensing applications. This review article aims to provide an overview of the latest developments in spinel-ferrite-based gas sensors. It begins by discussing the gas-sensing mechanism of spinel ferrite sensors, which involves the interaction between the target gas molecules and the surface of the sensor material. The unique properties of spinel ferrite, such as its high surface area, tunable bandgap, and excellent stability, contribute to its gas-sensing capabilities. The article then delves into recent advancements in gas sensors based on spinel ferrite, focusing on various aspects such as microstructures, element doping, and heterostructure materials. The microstructure of spinel ferrite can be tailored to enhance the gas-sensing performance by controlling factors such as the grain size, porosity, and surface area. Element doping, such as incorporating transition metal ions, can further enhance the gas-sensing properties by modifying the electronic structure and surface chemistry of the sensor material. Additionally, the integration of spinel ferrite with other semiconductors in heterostructure configurations has shown potential for improving the selectivity and overall sensing performance. Furthermore, the article suggests that the combination of spinel ferrite and semiconductors can enhance the selectivity, stability, and sensing performance of gas sensors at room or low temperatures. This is particularly important for practical applications where real-time and accurate gas detection is crucial. In conclusion, this review highlights the potential of spinel-ferrite-based gas sensors and provides insights into the latest advancements in this field. The combination of spinel ferrite with other materials and the optimization of sensor parameters offer opportunities for the development of highly efficient and reliable gas-sensing devices for early detection and warning systems.
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Schober, Sebastian A., Cecilia Carbonelli y Robert Wille. "Simulating Defects in Environmental Sensor Networks Using Stochastic Sensor Models". Engineering Proceedings 6, n.º 1 (17 de mayo de 2021): 88. http://dx.doi.org/10.3390/i3s2021dresden-10094.
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Chemiresistive gas sensors are an important tool for monitoring air quality in cities and large areas due to their low cost and low power and, hence, the ability to densely distribute them. Unfortunately, such sensor systems are prone to defects and faults over time such as sensitivity loss of the sensing material, less effective heating of the surface due to battery loss, or random output errors in the sensor electronics, which can lead to signal jumps or sensor stopping. Although these defects usually can be compensated, either algorithmically or physically, this requires an accurate screening of the entire sensor system for such defects. In order to properly develop, test, and benchmark corresponding screening algorithms, however, methods for simulating gas sensor networks and their defects are essential. In this work, we propose such a simulation method based on a stochastic sensor model for chemiresistive sensor systems. The proposed method rests on the idea of simulating the defect-causing processes directly on the sensor surface as a stochastic process and is capable of simulating various defects which can occur in low-cost sensor technologies. The work aims to show the scope and principles of the proposed simulator as well as to demonstrate its applicability using exemplary use cases.
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Dougami, Naganori, Takeshi Miyata, Taishi Orita, Tadashi Nakatani, Rui Kakunaka, Takafumi Taniguchi, Hirokazu Mitsuhashi y Shoichiro Nakao. "Hot-wire-type micromachined chemiresistive gas sensors for battery-powered city gas alarms". Japanese Journal of Applied Physics 64, n.º 1 (1 de enero de 2025): 01SP13. https://doi.org/10.35848/1347-4065/ada29c.
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Abstract Metal oxide semiconductor (MOX) chemiresistive gas sensors used in gas alarms have contributed to the safe use of city gas and liquid petroleum gas. In this study, we successfully fabricated hot-wire-type MOX sensors using micro-electro-mechanical systems (MEMS) technology. The hot-wire type structure, in which an electrode plays dual roles in detecting and heating, was adopted for efficient production. Owing to the miniaturization together with the thermal insulation, the sensors exhibited a fast thermal response. The average power consumption of the sensor in the pulsed operation was less than 100 μW. The sensor exhibited high sensitivity of more than 100 mV to 3000 ppm methane and showed low cross-sensitivity to interference gases such as ethanol and hydrogen. These sensing properties were retained for more than five years, demonstrating excellent long-term stability of the sensors.
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Huang, Baoyu, Xinwei Tong, Xiangpeng Zhang, Qiuxia Feng, Marina N. Rumyantseva, Jai Prakash y Xiaogan Li. "MXene/NiO Composites for Chemiresistive-Type Room Temperature Formaldehyde Sensor". Chemosensors 11, n.º 4 (21 de abril de 2023): 258. http://dx.doi.org/10.3390/chemosensors11040258.
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In this work, MXene/NiO-composite-based formaldehyde (HCHO) sensing materials were successfully synthesized by an in situ precipitation method. The heterostructures between the MXene and NiO nanoparticles were verified by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The HCHO sensing performance of the MXene/NiO-based chemiresistive-type sensors was investigated. Compared to pure MXene and NiO materials, the sensing performance of the MXene/NiO-P2-based sensor to HCHO gas at room temperature was significantly enhanced by the formation of MXene/NiO heterojunctions. The response of the MXene/NiO-P2 sensor to 50 ppm HCHO gas was 8.8, which was much higher than that of the pure MXene and NiO. At room temperature, the detectable HCHO concentration of the MXene/NiO-P2-based sensor was 1 ppm, and the response and recovery time to 2 ppm HCHO was 279 s and 346 s, respectively. The MXene/NiO-P2 sensor also exhibited a good selectivity and a long-term stability to HCHO gas for 56 days. The in situ Fourier transform infrared (FTIR) spectra of the MXene/NiO-P2 sensor, when exposed to HCHO gas at different times, were investigated to verify the adsorption reaction products of HCHO molecules.
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Yang, Taicong, Fengchun Tian, James A. Covington, Feng Xu, Yi Xu, Anyan Jiang, Junhui Qian, Ran Liu, Zichen Wang y Yangfan Huang. "Resistance-Capacitance Gas Sensor Based on Fractal Geometry". Chemosensors 7, n.º 3 (15 de julio de 2019): 31. http://dx.doi.org/10.3390/chemosensors7030031.
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An important component of any chemiresistive gas sensor is the way in which the resistance of the sensing film is interrogated. The geometrical structure of an electrode can enhance the performance of a gas-sensing device and in particular the performance of sensing films with large surface areas, such as carbon nanotubes. In this study, we investigated the influence of geometrical structure on the performance of gas sensors, combining the characteristics of carbon nanotubes with a novel gas sensor electrode structure based on fractal geometry. The fabricated sensors were tested with exposure to nitric oxide, measuring both the sensor resistance and capacitance (RC) of the sensor responses. Experimental results showed that the sensors with fractal electrode structures had a superior performance over sensors with traditional geometrical structures. Moreover, the RC characteristics of these fractal sensors could be further improved by using different test frequencies that could aid in the identification and quantification of a target gas.
Tesis sobre el tema "Chemiresistive gas sensor"
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KRIK, Soufiane. "Low-operating temperature chemiresistive gas sensors: Fabrication and DFT calculations". Doctoral thesis, Università degli studi di Ferrara, 2021. http://hdl.handle.net/11392/2488099.
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Despite advantages highlighted by Metal OXides (MOX) based gas sensors, these devices still present drawbacks in their performances (e.g. selectivity, stability and high operating temperature), so further investigations are necessary. Researchers tried to address these problems in several ways, which includes new synthesis methods for innovative materials based on MOX, such as solid solutions, addition of catalysts and doping of MOX by using external atoms or oxygen vacancies. Concerning this last issue, literature presents a lack of studies on how the arrangement and number of oxygen vacancies affect the sensing performance and only a few preliminary works highlighted interesting results. Another way to overcome MOX sensor drawbacks is to investigate novel class of materials, such as metal organic framework or 2D materials. Among these, phosphorene is one of the best candidates for such technological application, since it shows a chemoresistive activity at room temperature.
The goal of this work is to decrease the operating temperature of SnO2 based gas sensors by exploiting the oxygen vacancies. First, a theoretical investigation was done in the framework of Density Functional Theory (DFT) to investigate, on the atomic scale, how oxygen vacancies influence the physical and chemical properties of the material. The effect of oxygen vacancies on the structural, electronic and electrical properties of bulk SnO2 at two different concentrations was studied, then the formation of surface oxygen vacancies was investigated in order to study the adsorption of oxygen molecules from the surrounding atmosphere on the stoichiometric and reduced SnO2 surface. Then, reduced SnO2-x was synthesized and devices based on the produced material were fabricated and tested. The results showed a high response of the sensors towards low concentrations of nitrogen dioxide NO2 (500 ppb) at 130°C instead of the typical operating temperature of 450°C for SnO2-based gas sensors. This decrease in the operating temperature results in a decrease of the power consumption of the device, opening up to its possible employment on portable devices like mobile phones. The results were interpreted characterizing the material by mean of X-ray Powder Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope (SEM) and Ultraviolet–visible spectroscopy (UV-visible) analysis. In the end, the experimental results were compared to the DFT outputs obtained.
As mentioned before, phosphorene is one of the promising 2D materials for gas sensing applications, but it still presents some drawbacks, mainly due to the material degradation over the time when exposed to ambient conditions. Many investigations were done on decorating phosphorene with metal atoms in order to enhance its performance for different technological applications. Nickel is one of metals proposed for such purpose, but few studies were done on nickel decorated phosphorene for gas sensing applications, especially for gas sensing application. In the innovative work here proposed, DFT calculations were carried out to explain how nickel influences the electronic properties of phosphorene since the decoration with nickel showed better stability of the sensor and high response towards NO2 at room temperature. The theoretical results explained this behavior by studying the adsorption of oxygen molecules on pristine and nickel loaded phosphorene. The DFT calculations showed that oxygen molecules dissociate on the layer of pristine phosphorene and react with phosphorus atoms (oxidation of the material), while in the presence of the nickel atoms the later play the role of acceptors and interact with the oxygen molecules. Finally, the sensing mechanism towards NO2 was investigated theoretically by studying the charge transfer occurring at the surface of the material during the adsorption process.I sensori di gas basati sugli ossidi metallici semiconduttori (MOX) si sono rivelati negli ultimi anni una tecnologia estremamente vantaggiosa. Nonostante i progressi fatti in questo campo, questi dispositivi presentano ancora alcuni punti deboliche spingono la ricerca ad effettuare ulteriori indagini per perfezionare il loro funzionamento. I ricercatori hanno cercato di risolvere questi svantaggi in diversi modi, focalizzandosi sullo sviluppo di MOX innovativi, tra cui il drogaggio tramite l’utilizzo di additivi o l’introduzione nel materiale di vacanze di ossigeno a concentrazione controllata. Questa’alternativa sta attirando l’attenzione di molti gruppi di ricerca, anche se, ad oggi, la letteratura scientifica presenta una mancanza di studi su come la disposizione e concentrazione di vacanze di ossigeno influenzano le performance di sensing e solo alcuni lavori preliminari hanno portato a risultati interessanti. Per cercare di ovviare ai limiti dei sensori MOX, una seconda via è stata lo sviluppo e di materiali 2D basati su solfuri metallici, grafene o similari. Il fosforene è uno dei migliori candidati per tale applicazione tecnologica, poiché mostra un'attività elettrica anche a temperatura ambiente, anche se studi preliminari hanno evidenziato un alto tasso di degradazione nel tempo del materiale durante il suo utilizzo. L'obiettivo di questo lavoro è quello di diminuire la temperatura di funzionamento di sensori di gas basati su SnO2 sfruttando il controllo delle vacanze di ossigeno. A tale scopo, è stato fatto inizialmente uno studio della letteratura e un’analisi analitica nell’ambito della DFT per indagare come le vacanze di ossigeno influenzano le proprietà fisico-chimiche del materiale. È stato studiato l'effetto di due diverse concentrazioni di vacanze di ossigeno sulle proprietà chimico-fisiche dello SnO2 bulk. Successivamente è stata studiata la formazione della vacanze in superficie per investigare l'adsorbimento di molecole di ossigeno dall'atmosfera circostante sulla superficie dello SnO2 è stato sintetizzato tramite sintesi sol-gel e la riduzione è stata ottenuta tramite trattamento termico in presenza di H2 a diverse temperature. I risultati hanno mostrato un'alta risposta dei sensori basati su SnO2-x in presenza di basse concentrazioni di NO2 spostando a 130 °C la temperatura ottimale di funzionamento del dispositivo. Questa diminuzione della temperatura operativa implica una diminuzione del consumo energetico del dispositivo Come menzionato precedentemente, il fosforene è uno dei materiali 2D più promettenti per lo sviluppo di sensori di gas chemoresistivi, ma presenta ancora alcuni svantaggi. Molti studi sono stati sviluppati sulla decorazione del fosforene con atomi metallici al fine di migliorare le sue prestazioni per diverse applicazioni tecnologiche, ma non sono stati ancora condotti studi specifici su questa particolare forma di fosforene decorato per applicazioni di sensoristica gassosa. Nello studio qui proposto, sono stati eseguiti calcoli DFT per spiegare come il nichel influenzi le proprietà elettroniche del fosforene, poiché la decorazione con nichel ha mostrato una migliore stabilità del sensore e un’alta sensibilità all’NO2. Tramite simulazione DFT è stato possibile investigare l'adsorbimento delle molecole di ossigeno sul Fosforene tal quale e decorato con nichel. I risultati hanno evidenziato che le molecole di ossigeno si dissociano sullo strato di fosforene tal quale e reagiscono con gli atomi di fosforo, ossidandolo, mentre in presenza dei cluster di nichel è quest’ultimo a svolgere il ruolo di catalizzatore, interagendo con le molecole di ossigeno. Infine, il meccanismo di interazione tra NO2 e la superficie del fosforene tal quale e funzionalizzato è stato caratterizzato teoricamente studiando il trasferimento di carica che avviene sulla superficie del materiale in esame.
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Andio, Mark Anthony. "Sensor Array Devices Utilizing Nano-structured Metal-oxides for Hazardous Gas Detection". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343155831.
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Ni, Pingping. "Solution-processed functionalized MoS2 for room temperature NO2 chemiresistive sensors". Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAX117.
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Face aux enjeux environnementaux et liés à la santé publique, les capteurs de gaz toxiques et/ou polluants sont au cœur d’une recherche intensive et de moteurs d’innovation. Leur développement est d'une importance capitale et un enjeu majeur pour la société. Les capteurs à base d’oxyde métallique sont les plus étudiés et présentent beaucoup d’avantages tels que leur faible coût, une grande sensibilité et une intégration facile dans un système portable miniaturisé. Cependant, leurs températures de fonctionnement élevées limitent leur mise en œuvre dans les appareils portables et flexibles. Les matériaux 2D sont une classe émergente de matériaux, fonctionnant à température ambiante, ils suscitent un vif intérêt pour le développement de capteurs de gaz résistifs en raison de leurs excellentes flexibilités mécaniques, de leurs grandes surfaces spécifiques et actives, ainsi que leur haute sensibilité aux gaz. Dans cette famille, les chalcogénures de métaux de transition (TMDs), tels que le MoS2, présentent des propriétés exceptionnelles grâce à une bande interdite ajustable. Ils représentent des candidats prometteurs pour la détection des gaz toxiques à température ambiante.Dans ce contexte, l'objectif de cette thèse est de fabriquer et optimiser des capteurs résistifs de gaz toxiques à base du matériau 2D MoS2, par voie liquide, pour la détection de NO2. La première étape de ce travail a consisté au développement et à l’optimisation d’un procédé d’exfoliation en phase liquide afin de produire des suspensions colloïdales de nano-feuillets de MoS2 en grande quantité. En parallèle, nous avons évalué différents modes de dépôts permettant d’obtenir des films minces à partir de nano-feuillets individuels : la filtration sous vide et l'auto-assemblage à l'interface liquide/liquide. Différents types de caractérisations microscopiques et spectroscopiques, couplée avec des mesures électriques, ont été utilisées pour déterminer les conditions d’exfoliation optimales d'obtention de nano-feuillets de MoS2, ainsi que les propriétés structurales et électriques des couches minces fabriquées par les deux modes de dépôts différents. Une deuxième partie de ce travail a porté sur la conception et la réalisation de capteurs interdigités résistifs basées sur les couches minces fabriquées avec les nano-feuillets de MoS2. Ces capteurs montrent, à température ambiante, une bonne sensibilité à une faible concentration de NO2 de 1 ppm. Toutefois, la récupération complète après la détection du NO2 n’est pas systématique, dû en particulier à la génération de lacunes atomiques dans les nano-feuillets de MoS2 lors de l'exfoliation en phase liquide. Pour résoudre ce problème, nous passivions ces lacunes avec des nanoparticules d’or. La fonctionnalisation des nano-feuillets de MoS2 par des nanoparticules d’or augmentent la sensibilité vers le NO2 et réduit le temps de récupération par rapport au capteur de MoS2 seulIn response to environmental and public health issues, sensors for toxic and/or polluting gases are at the core of extensive research and innovation. Therefore, their development is important and also a major challenge for society. Up to date for gas sensing applications, metal oxide chemiresistive sensors are the most widely investigated devices thanks to their ease in fabrication, simplicity of operation, and facile integration in miniaturization. However, their high working temperature restricts their implementation in the wearable, flexible devices. Two-dimensional (2D) materials possess great potential in serving as a gas-sensing layer in wearable gas sensors due to their excellent mechanical flexibility, large specific surface areas, strong surface activities with a high gas sensitivity. Among this family, transition metal chalcogenides (TMDs), such as molybdenum disulfides (MoS2), exhibit outstanding properties thanks to its tunable band gap, and are also promising candidates for the detection of toxic gas at room temperature.This thesis aims to fabricate and optimize nitrogen dioxide (NO2) chemiresistive gas sensors based on solution-processed 2D MoS2. The first step in the work involved the development and the optimization of liquid phase exfoliation process to produce colloidal suspensions of MoS2 nanosheets on a large scale. In parallel, we assessed vacuum-assisted filtration and liquid/liquid interfacial self-assembly as two thin film fabrication techniques from individual nanosheets. Besides 2D MoS2 dispersion production and thin film processing, a multiscale physicochemical characterization of the produced MoS2 through microscopic and spectroscopic techniques, coupled with electrical measurements was conducted to determine the optimal exfoliation conditions to obtain MoS2 nanosheets and the morphologies of thin films produced by two distinct deposition processes. Then, MoS2 thin film fabricated by vacuum-assisted filtration with gold interdigitated electrodes on top were assessed for NO2 gas sensing, which exhibited a moderate sensitivity to a low NO2 concentration down to 1 ppm at room temperature. However, full recovery of NO2 sensing cannot always be achieved due to the MoS2 NSs atom vacancies generated during liquid shear exfoliation. To solve this issue, we passivated these vacancies on MoS2 nanosheets with gold nanoparticles (Au NPs). The functionalization of MoS2 nanosheets with Au NPs improved the sensitivity towards NO2 and lowered the recovery time compared to bare MoS2 sensor
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VIGNA, LORENZO. "Chemiresistive devices for room-temperature gas sensing applications: from loaded and intrinsically conductive polymers to layered double hydroxides". Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2967017.
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FENG, Zhifu. "Electron Beam Lithography and Focused Ion Beam Techniques for the Development of Low Power Consumption Microelectromechanical Systems-based Chemiresistive Gas Sensors". Doctoral thesis, Università degli studi di Ferrara, 2023. https://hdl.handle.net/11392/2502108.
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I sensori di gas sono ampiamente utilizzati per rilevare gas tossici per la protezione ambientale, il monitoraggio industriale, la sicurezza domestica, l'analisi del respiro e il deterioramento degli alimenti. A parte i sensori di gas elettrochimici, che hanno una breve durata, e i sensori di gas ottici di grandi dimensioni con un costo elevato, i sensori di gas chemiresistivi basati su ossidi metallici semiconduttori (OMS) risultano essere una soluzione tecnologica estremamente interessante, grazie alla sua bassa produzione costo, proprietà fisiche stabili e versatilità chimica. Tuttavia, per via dell'elevata temperatura operativa dei sensori di gas OMS, la riduzione del consumo energetico è di fondamentale importanza per una loro futura integrazione su dispositivi portatili, quali gli smartphones. A tale scopo, la miniaturizzazione dei sensori di gas OMS, principalmente per quanto riguarda il microriscaldatore, che funge da supporto meccanico del materiale di rilevamento e della parte riscaldatore/elettrodo, è un modo efficace per migliorare l'efficienza energetica. I sistemi microelettromeccanici (MEMS) offrono l'opportunità di raggiungere tale obiettivo. Questa dissertazione, focalizzata principalmente alla miniaturizzazione del microriscaldatore, si è concentrata sulla simulazione della dissipazione del calore del microriscaldatore mediante analisi agli elementi finiti, e sulla fabbricazione degli stessi utilizzando la litografia a fascio di elettroni (EBL) e il fascio di ioni focalizzati (FIB) per lo sviluppo di sensori di gas a bassissimo consumo energetico.
Quindi sono stati studiati e utilizzati due diversi approcci presso le strutture della Fondazione Bruno Kessler per fabbricare i microriscaldatori. Il primo metodo ha combinato le tecniche EBL e FIB per definire il layout del riscaldatore stesso. EBL è stato utilizzato per esporre la parte dell'elettrodo di dimensioni micrometriche, mentre il FIB è stato utilizzato per fresare la parte del circuito del riscaldatore con caratteristiche nanometriche. Nel secondo metodo, è stata utilizzata un'esposizione EBL in due fasi, senza utilizzo del FIB: i) bassa energia del fascio di elettroni con bassa dose e ampia area di scrittura per la definizione della struttura degli elettrodi; ii) alta energia del fascio di elettroni con dose elevata e piccolo campo di scrittura per la definizione del circuito del riscaldatore.
Dopo che questi microriscaldatori sono stati fabbricati, le loro proprietà elettriche e termiche sono state valutate sperimentalmente. Successivamente sono stati sviluppati sensori chemiresistivi sfruttando i microriscaldatori sviluppati. In particolare, il nanofilm ZnO di materiale sensibile di tipo n è stato depositato su MHP2 e NHP1 mediante magnetron sputtering. Il SEM ha rivelato le dimensioni nanometriche delle particelle di ZnO. La struttura cristallina di ZnO è stata caratterizzata dalla diffrazione della polvere di raggi X (XRD) e la spettroscopia fotoelettronica a raggi X (XPS) ha dimostrato il rapporto atomico di Zn e O. Il nanofilm di ZnO non ha mostrato una forte risposta all'umidità, mentre ha mostrato una buona sensibilità nei confronti del NO2.
Successivamente, i microriscaldatori MHP1 sono stati testati anche come substrati per sensori chemiresistivi a film spesso, utilizzando come materiale sensibile SnO2 altamente drogate con antimonio (ATO), concentrazione atomica del 10% e 15% in peso. Questi materiali sono stati caratterizzati da SEM, XRD e XPS, il che ha suggerito che il drogaggio di antimonio ha modificato la morfologia rispetto alla polvere di SnO2 non drogata, prevenendo la crescita delle particelle di polvere e diminuendo quindi la dimensione media delle nanoparticelle. La caratterizzazione XPS ha dimostrato che la concentrazione di antimonio era maggiore sulla superficie delle nanoparticelle di SnO2 rispetto al bulk. È stato riscontrato che i sensori ATO hanno portato a un’alta selettività e sensibilità all'NO2.Gas sensors are widely used for detecting toxic gases for environmental protection, industrial monitoring, household safety, breath analysis and food deterioration. Apart from the electrochemical gas sensors, which have a short lifetime, and optical gas sensors with large volume size with high cost, semiconductor metal oxide (SMO) gas sensors as one of the chemiresistive type gas sensors are now developing fast owing to its low production cost, stable physical properties and chemical versatility. However, regarding the high operational temperature of SMO gas sensors, reduction of power consumption is extremely important for its application in smartphones and other portable devices. For this purpose, miniaturization of SMO gas sensor devices, primarily for the hotplate part acting as mechanical support of the sensing material and heater/electrode part, is an effective way to improve the power efficiency. Microelectromechanical systems (MEMS) offer an opportunity to achieve such goal. This dissertation addressed to miniaturization of the hotplate, was focused on hotplate fabrication by using Electron Beam Lithography (EBL) and Focused Ion Beam (FIB). Then two different approaches were studied and used at Bruno Kessler Foundation facilities to microfabricate the hotplates. First method combined EBL and FIB techniques to define the layout. EBL was used to exposure the micro-level size electrode part (or pad part), and FIB was used to mill the heater circuit part with fine and dense structure. The patterned hotplate structure was characterized by Scanning Electron Microscope (SEM), and the milling result was analyzed by Secondary-ion Mass Spectrometry (SIMS). By studying these results, the optimized parameters for EBL and FIB were selected. The second method used two-step EBL exposure. Low energy of electron beam with low dose and large writing field for the electrode part exposure and high energy of electron beam with high dose and small writing field for the dense heater circuit patterning. After these hotplates were fabricated, their electrical and thermal properties were experimentally evaluated. Subsequently, chemiresistive sensors based on the developed hotplates were developed. In particular, n-type sensing material ZnO nano film was deposited on MHP2 and NHP1 by magnetron sputtering technique. SEM revealed the nano size of ZnO particle, and the calcination condition effect on the size of ZnO. ZnO crystal structure was characterized by X-ray Powder Diffraction (XRD), and X-Ray Photoelectron Spectroscopy (XPS) proved the atom ratio of Zn and O. ZnO nanofilm did not show strong response to humidity, but humidity could decrease the response toward NO2, and increase the response toward ethanol. Thick films of SnO2 highly doped by antimony with concentration of 10 wt% (ATO1) and 15wt% (ATO2) were drop coated on MHP1. These materials were characterized by SEM, XRD and XPS. It suggested that antimony doping modified the morphology of SnO2 powder by preventing the growth of powder particles. The results of the XPS experiment demonstrated that the concentration of antimony was higher on the surface of SnO2 than its inside. It was found that ATO sensors led to a particularly high selectivity and sensitivity to NO2 when compared to the other gases at 400 °C in dry air. Additionally, the sensing response of ATO1 and ATO2 was only moderately affected by humidity, which made them ideal candidates to detect NO2 in the actual atmosphere.
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DELLA, CIANA Michele. "Design, validation and future perspectives of a setup for operando DRIFT spectroscopy measurements on chemiresistive gas sensors". Doctoral thesis, Università degli studi di Ferrara, 2022. http://hdl.handle.net/11392/2481665.
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In questa tesi di dottorato è presentato lo sviluppo di un sistema operando per la caratterizzazione di sensori di gas chemiresistivi utilizzando spettroscopia di luce infrarossa (IR) diffusa (DRIFT).
L'attività di ricerca è stata focalizzata sullo sviluppo parallelo della camera test da implementare nello spettrometro e dell'elettronica associata per l'acquisizione e l'elaborazione dei segnali.
La camera di misura è stata progettata per essere compatibile con lo spettrometro a trasformata di Fourier IR Vertex V70 (Bruker) dotato di accessorio DRIFT Praying Mantis (Harrick Scientific).
Per il design meccanico della camera test si è fatto utilizzo sia delle tecnologie di stampa 3D, sia delle tecniche di lavorazione tradizionali di fresatura a controllo numerico.
L'elettronica del sistema è stata progettata per caratterizzare elettricamente sensori di gas chemiresistivi in un ampio intervallo dei parametri di misura (i.e., resistenza e temperatura operativa del film sensibile, umidità e temperatura dell'ambiente di lavoro).
Al sistema è associato un software, sviluppato in Java, che semplifica la caratterizzazione elettrica dei sensori, automatizzando alcune procedure di misura, come l'acquisizione della caratteristica corrente-tensione e della caratteristica corrente-temperatura.
Un sensore chemiresistivo è normalmente approssimato ad una resistenza ideale. L'implementazione di queste caratterizzazioni nell'elettronica di misura permette quindi di tenere in considerazione la non linearità di questa tipologia di dispositivi.
Il setup è stato validato sia utilizzando un sensore a base di un ossido metallico ampiamente utilizzato (ossido di stagno), sia caratterizzando un sensore basato su un innovativo semiconduttore non-ossido (carburo di silicio).
Nel primo caso il sensore a base di ossido di stagno è stato esposto a monossido di carbonio (CO) e idrogeno (H_2) in differenti condizioni termodinamiche (e.g. temperatura di lavoro, potenziale applicato al film sensibile e composizione dell'atmosfera) ed è stata studiata la correlazione fra lo spettro DRIFT e le proprietà elettriche del film sensibile.
L'analisi ha dimostrato la conformità del sistema operando per studiare l'interazione solido-gas, approfondendo la cinetica sulla superficie del film sensibile.
Il successivo studio riguardante dispositivi a base di carburo di silicio ha permesso di investigare il meccanismo di sensing nel rilevamento dell'anidride solforosa in condizioni di umidità controllata, monitorando lo stato di ossidazione che porta alla formazione di una core-shell SiC-SiO_xC.
Infine sono presentate due estensioni al sistema che permettono rispettivamente di effettuare misure operando DRIFT sia direttamente su polveri funzionali nano-strutturate in temperatura e sia su un sensore foto-attivato.This Ph.D. thesis presents the development of an operando setup for the characterization of chemiresistive gas sensors using diffused infrared light spectroscopy (DRIFT). The research activities were focused on the parallel development of a testing chamber to include in the spectrometer and the coupled electronics for the acquisition and the analysis of the electric signals. The measuring chamber was designed to be compatible with a Fourier transform IR spectrometer Vertex V70 (Bruker) equipped with the DRIFT praying Mantis accessory (Harric scientific). For the mechanical design of the chamber, it was exploited both 3D printing technologies and traditional numerical control manufacturing techniques. The electronics of the system was designed to electrically characterize chemiresistive gas sensors in a wide range of parameters (i.e., resistance and working temperature of the sensing film, relative humidity and temperature of the measuring environment). The system is managed by a software, written in Java, that simplifies the electrical characterization of the sensors, automating some measurement procedures, such as the acquisition of the current-voltage and current-temperature characteristics of the devices under test. A chemiresistive gas sensor is usually approximated by an ideal resistor, and the implementation of these characteristics in the measuring electronics allows to consider the non-linearity of this type of devices. The setup was validated both characterizing a metal-oxide based gas sensor (tin dioxide) and investigative a innovative gas sensor based on a non-oxide semiconductor (silicon carbide). In the first case, the sensor based on tin dioxide was exposed to carbon monoxide (CO) and hydrogen (H_2) in different thermodynamic conditions (e.g., working temperature and potential applied to the sensing film, composition of the atmosphere). It was studied the correlation between the DRIFT spectrum and the electrical properties of the sensing film. This analysis has demonstrated the compliance of the operando system to study the gas-solid interactions by deepening the kinetics on the surface of the sensing film. Afterward, the investigation on the devices based on silicon carbide nanoparticles allowed to understand the sensing mechanism of the sulfur dioxide detection under controlled humidity conditions. It was also monitored the oxidation state of the film, which leads to the formation of a SiC-SiO_xC core-shell. Finally, two extensions to the system are presented, that allow to perform operando DRIFT measurements at high temperature directly on powders and on photo-activated sensors, respectively.
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Sakhuja, Neha. "Two-Dimensional Nanomaterials for Chemiresistive Gas Sensors: Towards Development of Breath based Diagnostics". Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4800.
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Breath based Diagnostics (BbD) can enable a paradigm shift in the Point-of-Care Diagnostic (PoCD) devices. Exhaled human breath has been demonstrated to contain over 2000 volatile organic and inorganic compounds, some of which report marked change in concentration under diseases conditions. A sensitive, selective, cost effective and portable gas sensing system could thus non-invasively diagnose multiple diseases from a single breath sample. However, there is a need to develop highly sensitive gas sensors with very low limit of detection (LLoD) down to ppb to ppt and high selectivity to meet this requirement.
This thesis focuses on developing such gas sensors based on novel 2D nanomaterials and their hybrids while using a simple, scalable synthesis route. This is in contrast to the conventional choice of sensing materials (Metal Oxides, polymers, CNT’s etc.) and expensive fabrication methods. Here, we explored layered materials namely Transition Metal Dichalcogenides (TMDC) and Layered Transition metal oxides (TMO) and their hybrids for the detection of Ammonia (NH3), Hydrogen Sulphide (H2S) and Nitrogen Dioxide (NO2), three important constituents of exhaled breath. The synthesis of these layered materials was carried out at room temperature via the liquid phase exfoliation (LPE) technique using low boiling point solvents. This technique is attractive because it is simple, scalable and does not require sophisticated instrumentation.
The key findings from this work can be summarized as follows. Layered Transition metal oxide (TMO) namely 2D MoO3 based devices demonstrated reasonable response to NH3 at room temperature but only down to 300 ppb which was not sufficient for our intended application. Further, we observed that the layered TMD’s WS2, WSe2 and its hybrid with Fe3O4 demonstrate remarkable ammonia sensing. WS2 demonstrated high sensitivity towards NH3 (detection down to 50 ppb) with fair selectivity but at an elevated operating temperature of 250oC. On the other hand, WSe2/fe3O4 hybrid-based devices demonstrated enhanced sensitivity and selectivity towards ammonia, that too at room temperature, with a 50 ppb LLoD. Another notable observation was the similar response of pristine WSe2 nanosheets towards NO2 as NH3. Hence, we enhanced the NO2 sensing performance of WSe2 based sensors by functionalizing their surface with noble metals such as Au and Pt using a simple wet chemical route. Interestingly, we obtained highly sensitive (down to 100 ppb) and selective response towards NO2 at room temperature. More importantly, the complete recovery to the original baseline without any external energy source was remarkable since it is known to be challenging.
While exploring other inorganic TMO’s, we observed that 2D V2O5 based devices detect H2S non-selectively at 350oC and down to only 500 ppb. Further improvement in H2S sensing is helped by TMD’s again as we modified the surface of WS2 in such a manner that it suppressed NH3 sensing, by using low temperature microwave irradiation assisted synthesis technique. Thus, it demonstrated highly selective, sensitive, and prompt H2S detection, though at an elevated temperature of 250oC. Later, we observed that a novel material of this same class (1T-TiS2) could provide similar attributes at room temperature. This material was not investigated before for gas sensing; hence we conducted a theoretical study and presented a plausible mechanism based on vdW interaction, substantiating physisorption between adsorbate and adsorbent.
Thus, this thesis investigates novel materials, hybrids, and methods for scalable production of ultrasensitive, selective, stable, and low-cost sensors for NH3, H2S and NO2, which can potentially find applications for field-usable breath-based diagnostics in the futureMHRD, DEITY, DST Nanomission through NNeTRA
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Lin, Chung-Wen y 林崇文. "Chemiresistive-type NO gas sensor based on in situ synthesized poly(3,4-ethylenedioxythiophene)/3-thiophene carboxylic acid composite film". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/77088177129734412912.
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碩士臺灣大學
高分子科學與工程學研究所
98
In this study, 3,4-ethylenedioxythiophene (EDOT) was in situ oxidatively polymerized and doped with 3-thiophenecarboxylic acid (TCA) on a gold interdigitated electrode, and the resulted films were used as a resistive type gas sensor. The effects of the composition, ie. the ratio of [TCA]/[EDOT], and the acid/base treatment on the sensor response were investigated. The results showed that as the ratio of [TCA]/[EDOT] was increased, the sensor response to the exposure of 50 ppm NO gas was increased from nearly none to a slightly higher value of 2.2%. However, the sensor response can be further increased from 2.2 to 5.1% if the in situ synthesized film is to be treated with ammonia and hydrochloric acid sequentially during which the composite film is reduced, and the surface roughness increase. The temperature effect shows the optimum operation temperature is at room temperature. The sensor showed linear response in the concentration between 1 and 10 ppm. The sensitivity for the PEDOT/TCA composite sensor is ~0.93%/ppm. The limit of detection is 25 ppb (S/N = 3). The response time (t95) and recovery time (t95) were recorded to be 756 s and over 1 hr. respectively. The long-term stability was also tested for a month, which shows no obvious decay in sensitivity. The long recovery time (> 1 hr) appeared in the PEDOT/TCA composite film was also overcome (~10 min) by heating the sensor during recovery. Keywords: resistive type gas sensor, oxidatively polymerization, in situ polymerization, EDOT, 3-thiophenecarboxylic acid (TCA), interdigitated electrode, nitric oxide.
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Yu, Ti-Ching y 游狄憬. "Gas sensing characteristics of carbon nanotubes-polymer composites chemiresistive vapor sensors". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/13185181631766517275.
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碩士國防大學中正理工學院
應用化學研究所
96
The feasibility of thin-film chemical sensors based on carbon nanotubes-functional polymer nanocomposite to reliably detect chemical gas has been studied. The sensors were exposed to mixtures of dimethyl-methyl-phosphonate(DMMP), 3,4,5-Trimethoxy- benzylamine (345-TB) , acetonitrile(AN) 、 2-Bromoacetophenone（2-BAP）、Dichloromethane（DCM）with air., respectively. Therefore, a series of nanocomposite sensor array was composed of more sensing functional polymers with multiwalled carbon nanotubes (MWCNTs). The chemiresistive sensors array representing different polymer concentrations were constructed by depositing thin films of a carbon nanotubes-polymer nanocomposite onto golden electrodes on a wafer laminate substrate. The sensors are carbon nanotubes-polymer nanocomposite films, which swell reversibly and cause a resistance change upon exposure to a wide variety of chemical gas. Finally, The post processed data was then subjected to a principal component analysis, a pattern recognition technique, for chemical gas discrimination.
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Chang, Chia-Lin y 張佳琳. "Adaptive Interface Circuits of Chemiresistive Gas Sensors for an Electronic Nose System". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/10918564993598900464.
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碩士國立清華大學
電機工程學系
102
Many odors are not suitable for human to smell, such as poisonous and exhausted gases. In addition, olfaction is different from person to person. Compare to the traditional gas detection instrument, an electronic nose (E-nose) system has various advantages including small size, low cost, low power, quantization of olfaction, and the capability of being exposed to dangerous gases. Therefore, it can be applied to quality control of foods, environmental monitoring, pollution measurement and disease diagnosis, etc. E-nose system is composed of a gas sensor array, a signal acquisition circuit and a pattern recognition system. Conducting polymer sensor is one of the chemiresistive gas sensors. It has the advantages of working at room temperature, high sensitivity (about a few ppm), and its readout circuit is simple, which would be suitable for portable devices. However, the sensor resistance could be easily affected by temperature, humidity, and background odors. In addition, the resistances of each sensor in the sensor array are not the same after the deposition of different sensing materials. Therefore, an adaptive interface circuit is required to cancel the baseline drift and read the sensor signal. Three types of adaptive interface circuits fabricated by TSMC 0.18μm CMOS 1P6M processes would be introduced in this paper: semi-digital type, digital type and analog type. Simulation and measurement result of these three interface circuits would be presented and be compared. Lastly, an external conductive polymer gas sensor array connected with adaptive interface circuit was exposed to different odors, and the results were presented. Gas sensors were respectively integrated with the semi-digital type and digital type interface circuits on the same chip.
Libros sobre el tema "Chemiresistive gas sensor"
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Hoa, Nguyen Duc y Shivani Dhall. Carbon Nanomaterials and their Nanocomposite-Based Chemiresistive Gas Sensors: Applications, Fabrication and Commercialization. Elsevier, 2022.
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Hoa, Nguyen Duc y Shivani Dhall. Carbon Nanomaterials and Their Nanocomposite-Based Chemiresistive Gas Sensors: Applications, Fabrication and Commercialization. Elsevier, 2021.
Buscar texto completoCapítulos de libros sobre el tema "Chemiresistive gas sensor"
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Verma, Gulshan y Ankur Gupta. "Theoretical Studies of Nanomaterials-Based Chemiresistive Gas Sensor". En Gas Sensors, 13–27. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003278047-3.
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Rani, Sanju, Manoj Kumar, Yogesh Singh, Rahul Kumar y V. N. Singh. "Metal Oxide/CNT/Graphene Nanostructures for Chemiresistive Gas Sensors". En Chemical Methods for Processing Nanomaterials, 163–94. First edition. | Boca Raton : CRC Press, Taylor & Francis Group, 2021.: CRC Press, 2020. http://dx.doi.org/10.1201/9780429023187-10.
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Ramgir, Niranjan, Ankita Pathak, K. R. Sinju, Bhagyashri Bhangare, A. K. Debnath y K. P. Muthe. "Chemiresistive Sensors for H2S Gas: State of the Art". En Recent Advances in Thin Films, 625–63. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6116-0_19.
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Nair, Keerthi G., V. P. Dinesh y P. Biji. "Metal Oxide Based Heterojunction Nanoscale Materials for Chemiresistive Gas Sensors". En Advances in Nanostructured Composites, 161–201. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018] | Series: Advances in nanostructured composites ; volume 2 | “A science publishers book.»: CRC Press, 2019. http://dx.doi.org/10.1201/9780429021718-9.
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Pirsa, Sajad. "Chemiresistive Gas Sensors Based on Conducting Polymers". En Handbook of Research on Nanoelectronic Sensor Modeling and Applications, 150–80. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0736-9.ch006.
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Chemiresistive gas sensor based on conducting polymer is a type of sensors that presents gas sensors with excellent characters; low-cost fabrication, fast detection, simultaneous determination (array gas sensor), portable devices and so. Theses gas sensors are commonly based on polyaniline (PANI), polypyrrole (PPy), polythiophene (PTh) and their derivatives as a transducer. Common configuration and response mechanism of these sensors are reported in this section. Some factors that induce selectivity to these sensors are discussed. Different materials (conductor or insulant) can be used as a substrate of polymerization. Type of substrate, selective membranes, surface modification of conducting polymer and so can change response behavior of these sensors.
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Pirsa, Sajad. "Chemiresistive Gas Sensors Based on Conducting Polymers". En Materials Science and Engineering, 543–74. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1798-6.ch022.
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Chemiresistive gas sensor based on conducting polymer is a type of sensors that presents gas sensors with excellent characters; low-cost fabrication, fast detection, simultaneous determination (array gas sensor), portable devices and so. Theses gas sensors are commonly based on polyaniline (PANI), polypyrrole (PPy), polythiophene (PTh) and their derivatives as a transducer. Common configuration and response mechanism of these sensors are reported in this section. Some factors that induce selectivity to these sensors are discussed. Different materials (conductor or insulant) can be used as a substrate of polymerization. Type of substrate, selective membranes, surface modification of conducting polymer and so can change response behavior of these sensors.
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Fang, Yunnan. "Converting Silver Electrodes into Porous Gold Counterparts: A Strategy to Enhance Gas Sensor Sensitivity and Chemical Stability via Electrode Engineering". En Gold Nanoparticles and Their Applications in Engineering. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.110654.
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This chapter describes a strategy for sensitivity and chemical stability enhancement of chemiresistive gas sensors via electrode engineering. In this strategy, flexible chemiresistive gas sensors were fabricated by uniformly depositing functionalized semiconducting carbon nanotubes (CNTs) on a polyimide substrate via a novel layer-by-layer wet chemical method, followed by inkjet printing fine-featured silver interdigitated electrodes (IDEs) on the substrate. The electrode engineering was realized by converting the inkjet-printed IDEs into their highly porous and chemically stable gold counterparts via a mild and facile two-step process, with the substrate-IDE adhesion retained. As a proof-of-concept demonstration, a diethyl ethylphosphonate (DEEP, a simulant of the nerve agent sarin) sensor equipped with inkjet-printed dense silver IDEs was converted into its counterpart equipped with highly porous gold IDEs. The resulting gold-electrode gas sensor exhibited sensitivity to DEEP of at least fivefold higher than a similar sensor electrode with the dense silver IDEs. The sensitivity enhancement was probably due to the catalytic activity of the resulting gold IDEs, as well as the creation of the nano−/micro-scale pores in the gold IDEs that increased the Schottky contacts between the gold IDEs and the semiconducting CNTs.
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Veerla, Sarath Chandra, N. V. S. S. Seshagiri Rao y Anil Kumar Astakala. "Fabrication of chemiresistive gas sensor with carbon materials/polymers nanocomposites". En Carbon Nanomaterials and their Nanocomposite-Based Chemiresistive Gas Sensors, 205–22. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-12-822837-1.00003-4.
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Bandi, Suresh y Ajeet K. Srivastav. "Graphene-based chemiresistive gas sensors". En Analytical Applications of Graphene for Comprehensive Analytical Chemistry, 149–73. Elsevier, 2020. http://dx.doi.org/10.1016/bs.coac.2020.08.006.
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Kumar, Sandeep, Arshdeep Singh y Anil Kumar Astakala. "Carbon nanomaterial-based chemiresistive sensors". En Carbon Nanomaterials and their Nanocomposite-Based Chemiresistive Gas Sensors, 107–31. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-12-822837-1.00001-0.
Texto completoActas de conferencias sobre el tema "Chemiresistive gas sensor"
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Orlando, Antonio, Andrea Gaiardo, Matteo Valt, Guglielmo Trentini, Marco Magoni, Pietro Tosato, Soufiane Krik, Paolo Lugli, Luisa Petti y Leandro Lorenzelli. "Towards Flexible & Wearable Diabetes Monitoring: Printing of Metal Oxide Materials for Chemiresistive Gas Sensors". En 2024 IEEE International Flexible Electronics Technology Conference (IFETC), 1–4. IEEE, 2024. https://doi.org/10.1109/ifetc61155.2024.10771847.
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Joubert, Trudi-Heleen, Jurie du Toit, Bonex Mkwakikunga y Peter Bosscha. "Handheld chemiresistive gas sensor readout system". En Fourth Conference on Sensors, MEMS and Electro-Optic Systems, editado por Monuko du Plessis. SPIE, 2017. http://dx.doi.org/10.1117/12.2245787.
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Darunkar, Swapnil S., S. C. Shirbhate, P. R. Chaudhari y S. A. Acharya. "Ethanol sensing behaviour of Pd-doped ZnO thin film based chemiresistive gas sensor". En 3RD INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC-2019). AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0001828.
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Ye, Xiao, Tianshu Jiang, Lingpu Ge, Fumihiro Sassa, Chuanjun Liu y Kenshi Hayashi. "Paper-based Chemiresistive Gas Sensor Using Molecularly Imprinted Sol-Gels for Volatile Organic Acids Detection". En 2021 IEEE Sensors. IEEE, 2021. http://dx.doi.org/10.1109/sensors47087.2021.9639251.
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Chiu, Shih-Wen, Jen-Huo Wang, Kwuang-Han Chang, Hiang-Chiu Wu, Hsin Chen, Chih-Cheng Hsieh, Meng-Fan Chang, Guoxing Wang y Kea-Tiong Tang. "A signal acquisition and processing chip with built-in cluster for chemiresistive gas sensor array". En 2014 IEEE 12th International New Circuits and Systems Conference (NEWCAS). IEEE, 2014. http://dx.doi.org/10.1109/newcas.2014.6934074.
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Sharma, Anshul Kumar, Pankaj Kumar, Rajan Saini, R. K. Bedi y Aman Mahajan. "Kinetic response study in chemiresistive gas sensor based on carbon nanotube surface functionalized with substituted phthalocyanines". En INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2015): Proceeding of International Conference on Condensed Matter and Applied Physics. Author(s), 2016. http://dx.doi.org/10.1063/1.4946544.
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Yan, Yiran, Miluo Zhang, Heng Chia Su, Nosang V. Myung y Elaine D. Haberer. "Toward a chemiresistive ammonia (NH3) gas sensor based on viral-templated gold nanoparticles embedded in polypyrrole nanowires". En SPIE NanoScience + Engineering, editado por Norihisa Kobayashi, Fahima Ouchen y Ileana Rau. SPIE, 2014. http://dx.doi.org/10.1117/12.2062183.
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Krivec, Matic, Raimund Leitner, Roland Waldner, Johanna Gostner y Florian Überall. "The effect of sensor temperature and MOx layer thickness on the sensitivity of SnO2- and WO3-based chemiresistive sensors to ethylene gas". En SPIE Microtechnologies, editado por José Luis Sánchez-Rojas y Riccardo Brama. SPIE, 2015. http://dx.doi.org/10.1117/12.2179235.
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Naganaboina, Venkata Ramesh, Satish Bonam y Shiv Govind Singh. "Selective Detection of H2S Gas Using a Tin (II) Sulfide Based Chemiresistive Sensor with Schottky Contact". En 2023 IEEE International Conference on Flexible and Printable Sensors and Systems (FLEPS). IEEE, 2023. http://dx.doi.org/10.1109/fleps57599.2023.10220226.
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Spasenovic, M., S. Andric y T. Tomasevic-Ilic. "Graphene-based Chemiresistive Gas Sensors". En 2021 IEEE 32nd International Conference on Microelectronics (MIEL). IEEE, 2021. http://dx.doi.org/10.1109/miel52794.2021.9569192.
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